1. Technical Field
The present disclosure relates to mapping and modeling data and, more particularly, to systems and methods for processing mapping and modeling data.
2. Description of the Background Art
Maps enhance the value of positioning by effectively converting position information of natural and man-made objects, persons, vehicles and structures to location information. Outdoor mapping such as street mapping capability has been announced by companies Navteq and Tele-Atlas. These outdoor location services are GPS-based in that they acquire and use GPS signals to obtain precise position and location information for positioning and mapping. One example is discussed in U.S. Pat. No. 6,711,475. This patent, as well the other patents identified or described herein, are incorporated herein by reference.
Where GPS signals are not available or not dependable (such as indoors) attempts have been made to determine position or location. U.S. Pat. No. 5,959,575 describes the use of a plurality of ground transceivers which transmit pseudo-random signals to be used by a mobile GPS receiver indoors.
In mining operations where GPS signals are not available, U.S. Pat. No. 6,009,359 describes the use of an Inertial Navigation System (INS) to determine position, and obtaining image frames which are tiled together to get a picture of inside the mine. U.S. Pat. No. 6,349,249 describes a system for obtaining mine Tunnel Outline Plan views (TOPES) using an inertial measurement unit (IMU). U.S. Pat. No. 6,608,913 describes a system for obtaining point cloud data of the interior of a mine using an INS, to thereafter locate a position of a mining vehicle in the mine.
In indoor facilities such as buildings, U.S. Pat. No. 7,302,359 describes the use of an IMU and rangefinder to obtain a two-dimensional map of the building interior, such as wall and door locations. U.S. Pat. No. 6,917,893 describes another indoor mapping system for obtaining two-dimensional or three-dimensional data using an IMU, laser rangefinder and camera.
U.S. Patent Application Publication No. 2009/0262974 to Erik Lithopoulos (the Lithopoulos application) relates to a system and method for acquiring geospatial data information including a positioning device for determining the position of surface data points of a structure in three-dimensions in a region unable to receive adequate GPS signals. The Lithopoulos application is incorporated herein by reference and is considered as forming a part of the present disclosure. The system is capable of obtaining ranging, imaging and position data of a premises undergoing scanning. The system correlates the position and image data for the data points. Utilizing the stored data, three dimensional geographical coordinates of the surface data points may then be calculated and stored. Image data of the points from the image capture device may be draped over the surface data points to provide and store texture and color for those points. This process continues from point to point thereby forming a cloud (point cloud) of georeferenced positions data. Utilizing, the stored data, a processor can reconstruct an image of a mapped interior surface area of the premises. The Lithopoulos application thus provides a useful tool for mapping the interior environment of a structure such as a building.
The subject matter of the present application is complementary to the Lithopoulos application and is a useful tool for facilitating the generation of clear, non-blurry mapping images. Mapped digital images can sometimes by blurry because the accuracy of location determining systems capable of use in areas not accessible to GPS signals can be limited. For example, inertial and odometry systems have inherent errors in their location determining capabilities. This error in turn, effects locating of the three dimensional geographical coordinates of the surface data points, thus resulting in a “blur” when the point cloud is generated.
Sensor technologies that will not only operate indoors but will do so without relying on building infrastructure provide highly desirable advantages for public safety crews, such as firefighters, law enforcement including SWAT teams, and the military. The need for such indoor mapping has increased due to the ever increasing concern to protect the public from terrorist activity especially since terrorist attacks on public, non-military targets where citizens work and live. In addition to terrorist activity, hostage activity and shootings involving student campuses, schools, banks, government buildings, as well as criminal activity such as burglaries and other crimes against people and property have increased the need for such indoor mapping capability and the resulting creation of displayable information that provides a virtual travel through interior regions of a building structure.
What is needed is a system and method for three dimensional mapping of regions, especially those regions where GPS signal information is not available or is unreliable such as within a building structure, and for showing the location and boundaries of interior objects and structures, as well as characteristic image data such as color, reflectivity, brightness, texture, lighting, shading and other features of such structures, whereby such data may be processed and displayed to enable a virtual tour of the mapped region. In particular, the mobile system and method described herein are capable of generating indoor maps that are highly accurate and clear and can be produced quickly by simply walking through the interior areas of a building structure to obtain the data needed to create the maps without the use of support from any external infrastructure or the need to exit the indoor space for additional data collection. In addition, the subject matter of the application includes a system and method for providing such indoor location information based upon the operator's floor, room and last door walked through, which information can be provided by combining position information with an indoor building map. Moreover, a mobile mapping system and method is described by which high-rate, high-accuracy sensor, position and orientation data are used to geo-reference data from mobile platforms. A benefit of geo-referencing data from a mobile platform is increased productivity since large amounts of map data may be collected over a short period of time.